All mtDNA haplogroups found outside of Africa are descendants of either haplogroup N or its sibling haplogroup M. M and N are the signature haplogroups that define the out of Africa migration and the subsequent spread to rest of the world. The global distribution of haplogroups N and M, indicates that very likely, there was one particularly major prehistoric migration of humans out of Africa, and both N and M were part of the same colonization process.[10]

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Suggested routes of the initial settlement of Europe based on mtDNA haplogroups M and N, Metspalu et al. 2004. A major population split near the Persian Gulf would explain the ubiquity of Haplogroup N and the absence of Haplogroup M in West Eurasia

There is widespread agreement in the scientific community concerning the African ancestry of haplogroup L3 (haplogroup N's parent clade).[11] However, whether or not the mutations which define haplogroup N itself first occurred within Asia or Africa has been a subject for ongoing discussion and study.[11]

The out of Africa hypothesis has gained generalized consensus. However, many specific questions remain unsettled. To know whether the two M and N macrohaplogroups that colonized Eurasia were already present in Africa before the exit is puzzling.

Torroni et al. 2006 state that Haplogroups M, N and R occurred somewhere between East Africa and the Persian Gulf.[12]

Also related to the origins of haplogroup N is whether ancestral haplogroups M, N and R were part of the same migration out of Africa, or whether Haplogroup N left Africa via the Northern route through the Levant, and M left Africa via Horn of Africa. This theory was suggested because haplogroup N is by far the predominant haplogroup in Western Eurasia, and haplogroup M is absent in Western Eurasia, but is predominant in India and is common in regions East of India. However, the mitochondrial DNA variation in isolated "relict" populations in southeast Asia and among Indigenous Australians supports the view that there was only a single dispersal from Africa. Southeast Asian populations and Indigenous Australians all possess deep rooted clades of both haplogroups M and N.[10] The distribution of the earliest branches within haplogroups M, N, and R across Eurasia and Oceania therefore supports a three-founder-mtDNA scenario and a single migration route out of Africa.[13] These findings also highlight the importance of Indian subcontinent in the early genetic history of human settlement and expansion.[14]

The hypothesis of Asia as the place of origin of haplogroup N is supported by the following:

Haplogroup N is found in all parts of the world but has low frequencies in Sub-Saharan Africa. According to a number of studies, the presence of Haplogroup N in Africa is most likely the result of back migration from Eurasia.[4]

The oldest clades of macrohaplogroup N are found in Asia and Australia.

It would be paradoxical that haplogroup N had traveled all the distance to Australia or New World yet failed to affect other populations within Africa besides North Africans and Horn Africans.

N1 is the only sub-clade of haplogroup N that has been observed in Africa. However N1a is the only one in East Africa: this haplogroup is even younger and is not restricted to Africa, N1a has also been detected in Southern Siberia and was found in a 2,500-year-old Scytho-Siberian burial in the Altai region.[15]

The mitochondrial DNA variation in isolated "relict" populations in southeast Asia supports the view that there was only a single dispersal from Africa.[10] The distribution of the earliest branches within haplogroups M, N, and R across Eurasia and Oceania provides additional evidence for a three-founder-mtDNA scenario and a single migration route out of Africa.[13] These findings also highlight the importance of Indian subcontinent in the early genetic history of human settlement and expansion.[14] Therefore N’s history is similar to M and R which have their most probably origin in South Asia.

According to Toomas Kivisild "the lack of L3 lineages other than M and N in India and among non-African mitochondria in general suggests that the earliest migration(s) of modern humans already carried these two mtDNA ancestors, via a departure route over the Horn of Africa.[7]

Haplogroup N is derived from the ancestral L3 haplotype that represents the 'Out of Africa' migration. Haplogroup N is the ancestral haplogroup to almost all European and Oceanian haplogroups in addition to many Asian and Amerindian ones. It is believed to have arisen at a similar time to haplogroup M. Subclades such as Haplogroup U6, are also found at moderate to low frequencies in the Northwest and East Africa, due to a back migration from Asia around 27,000 years ago.[1][3]

This phylogenetic tree of haplogroup N subclades is based on the paper by Mannis van Oven and Manfred Kayser Updated comprehensive phylogenetic tree of global human mitochondrial DNA variation[9] and subsequent published research.